Experts say most diseases can’t be eliminated, so improving living conditions and reducing suffering are as important as finding a vaccine.

One summer day in 1953, 13-year-old Richard Daggett woke up with a terrible backache.

Putting on clothes that morning was uncomfortable and bending over to tie his shoelaces was especially painful.

He’d had a bad headache the day before but “this back thing was different. I’d never known anything like this.”

The family doctor sent him to the hospital, where he was admitted and given a spinal tap. It was to test for polio, the doctors told him.

Daggett had heard of polio, mostly from posters about the March of Dimes, but it had never occurred to him to worry about it.

That night, however, when he tried to reach out for the bedpan on the hospital nightstand, he could barely move his arms.

“I wasn’t sure how a person was supposed to feel if they had polio, but not being able to sit up told me I had it,” Daggett wrote in his memoir. “I distinctly remember saying to myself, ‘Uh-oh. I think I have it.’”

Daggett had been caught up in the United States polio epidemic that peaked in 1952 with more than 21,000 people experiencing paralysis from the virus. It was a national crisis that ended abruptly in the mid-1950s when a successful vaccine was announced and administered to children on a broad scale.

The last U.S. polio case was in 1979.

Read More: Amazon Jungle Tribes Facing Modern Day Health Threats »

In some ways, eliminating polio from the U.S. mirrors the eradication of smallpox worldwide.

Like polio, an effective vaccine was crucial to wiping out this ancient scourge. There hasn’t been a case of smallpox anywhere since 1977.

These two public health miracles raised public expectations of what medical research can deliver. But only smallpox and rinderpest — a measles-like virus that kills cattle — have been truly eradicated from the globe.

Where are the rest of our miracles?

A long way off, most scientists agree.

“With present knowledge, present facilities, and present equipment, few diseases should be put into a discussion of eradication,” Dr. Philip Brachmann, a professor at Emory University’s School of Public Health, told Healthline.

On a list of what makes a disease eradicable, a lot of boxes must be checked off.

First, it has to be easy to diagnose and it can’t lie dormant in a patient for a long period of time.

It must rise and decline cyclically and induce natural immunity in survivors.

Also, it can’t have an animal reservoir, like mosquitos or armadillos. Those animals would have to be driven to extinction in order to get rid of the germ.

Any vaccine or treatment must be easy to administer and cost-effective.

Finally, it has to be severe and widespread enough to warrant the attention of governments and public health officials.

Read More: Researchers Closer to HIV Vaccine Than Ever Before »

According to the Carter Center, seven diseases meet those qualifications and are currently targets of eradication campaigns.

Guinea worm eradication is probably closest at hand.

For other diseases, it may be more worthwhile to focus on improving quality of life for people in affected areas rather than embarking on a specific eradication operation.

For example, deaths from infectious diseases in the U.S. throughout the 20th century were on the decline even before the advent of penicillin and vaccines.

The establishment of public health departments, cleaner drinking water, and specific public health campaigns such as the shoeing of barefoot children in Southern states were all instrumental in precipitating this decline.

Similar efforts could curb some of the diseases grabbing headlines today.

The Zika virus, which is spread by mosquitos, could be slowed by cleaning up the slums that make good mosquito breeding grounds, Randall Packard, PhD, a historian of science at Johns Hopkins University, told Healthline.

And the Ebola outbreak in West Africa, he said, would have been less devastating if there were better access to primary care in those countries.

Vaccine development might get the lion’s share of attention, he said, but focusing solely on vaccines would ignore the underlying problem.

“So we get a vaccine that saves the day but we haven’t done anything about those conditions that have generated the diseases or allowed them to spread,” Packard said.

Dr. Mark Rosenberg, the president of The Task Force for Global Health, sees this as a false dichotomy.

“It’s not either you build primary care or eliminate diseases,” he told Healthline. “It’s really important that you do both synergistically.”

For example, he said, as primary care programs are strengthened in developing countries, they should include surveillance programs to detect and report outbreaks.

Read More: The Underreported Epidemic of HIV in U.S. Women »

Daggett ended up spending six months in an iron lung and about three years in the hospital.

He was still there when news broke of the first successful polio vaccine. Nearly everybody on the ward cheered, he told Healthline, except for one young man who muttered, “You’re a little late, guys.”

While not all diseases are as vulnerable to human intervention as polio, there is much that can be done to alleviate human suffering.

It depends, in part, on a shift in the Western perspective, Rosenberg noted.

“We can’t wait for diseases to become threats to us over here,” he said. “We need to be aware of and respond to diseases that are threats to them over there. The degree of threat it presents to us is not the only reason we need to respond.

We respond because we share a common humanity and things that injure, kill, sicken, or weaken other people over there affect us because we care about them.”